The invention relates to oil injection systems for two cycle internal combustion engines, for providing a fuel-oil mixture to the engine.
It is known in the art to provide an oil injection system using an oil pump driven by a worm gear arrangement on the crankshaft for example U.S. Pat. No. 4,512,292, and Outboard Service Training Notebook, Brunswick Corp. Bulletin 90-90592 3-1286, pages 108-109. The amount of pumped oil is varied by an adjusting lever on the oil pump. It is also known in the art to provide fuel-oil mixing valves with oil pumping chambers, wherein the amount of oil pumped and the fuel-oil ratio is determined by the volume of such chamber, for example U.S. Pat. No. 4,583,500.
The present invention provides a particularly simple, low cost oil injection system, and also provides accurate control of the fuel-oil ratio .